Das Zerstäuben als Grundverfahren

Atomization as a unit process. Liquid atomization can be classified by three successive steps: disintegration; multiphase flow in the spray; and impact of droplets on the substrate. The most important process parameter is the size distribution of the droplets. By means of this parameter the liquid disintegration process can be related to the different transport phenomena in the spray or to the impacting process. The size distribution of the droplets is not a static parameter but an evolving result of local changes depending on sifting effects, on strand formation, on coalescence, on evaporation, on drying or chemical reaction processes. It is thus essential, for further analysis, to start from local instead of integral size distributions. This will be possible because of the efficiency of new particle sizing instruments with high spatial or temporal resolution. This opens the possibility for differential instead of integral balance. From this one can derive, for the future, higher precision of apparatus design and improved optimization procedures for process design. Finally, appropriate measuring techniques are discussed with regard to their special applicability to liquid atomization analysis.